While drilling, drilling fluids or drilling mud may be delivered to the drill string through a washpipe system. From a top drive and associated wash pipe, the fluids are transported and supplied to the drill string. The drill string generally extends through an opening in a rig floor, through a bell nipple assembly and through a blow out preventer before entering into a wellbore.
The bell nipple assembly and blow out preventer are often coupled together below the rig floor. The bell nipple assembly, which funnels drilling tools into the blow out preventer or downhole, is generally located above the blow out preventer. The blow out preventer is attached to an annular near a wellhead. When the annular is cut at an angle, a longitudinal axis of the blow out preventer that is attached to the annular is often not coaxial with a longitudinal axis of the wellhead, which can result in an offset between longitudinal axes. Additionally, the blow out preventer may be replaced during a pause in drilling, or the bell nipple assembly may be moved to a drilling location that has a blow out preventer with a different connection height or connection diameter. This can require the removal or exchange of the bell nipple assembly for another bell nipple assembly that is compatible with the new blow out preventer. Moreover, drilling fluids often escape at a location between the bell nipple assembly and the rig floor.
The present disclosure is directed to apparatuses and methods to address these problems. Thus, the present disclosure provides a unique structural arrangement adjustable to different heights to couple the blow out preventer to the rig floor, while adjusting offset between the longitudinal axes of the blow out preventer and the wellbore and minimizing or preventing the drilling fluid from spilling out the bell nipple assembly or any gap between it and the rig floor.